Move from master to main (step1) (#531)

Author: reyang

.github/ISSUE_TEMPLATE/bug_report.md

@@ -4,7 +4,7 @@ about: Create a report to help us improve
 labels: bug
 ---
 
-**Describe your environment** Describe any aspect of your environment relevant to the problem, including your platform, build system, version numbers of installed dependencies, etc. If you're reporting a problem with a specific version of a library in this repo, please check whether the problem has been fixed on master.
+**Describe your environment** Describe any aspect of your environment relevant to the problem, including your platform, build system, version numbers of installed dependencies, etc. If you're reporting a problem with a specific version of a library in this repo, please check whether the problem has been fixed on main branch.
 
 **Steps to reproduce**
 Describe exactly how to reproduce the error. Include a code sample if applicable.

.github/workflows/ci.yml

@@ -2,9 +2,9 @@ name: CI
 
 on:
   push:
-    branches: [ master ]
+    branches: [ main, master ]
   pull_request:
-    branches: [ master ]
+    branches: [ main, master ]
 
 jobs:
   cmake_test:

CONTRIBUTING.md

@@ -28,7 +28,7 @@ example-specific documentation for other build automation tools.
 Install the latest bazel version by following the steps listed
 [here](https://docs.bazel.build/versions/master/install.html).
 
-Select an example of interest from the [examples folder](https://github.com/open-telemetry/opentelemetry-cpp/tree/master/examples).
+Select an example of interest from the [examples folder](https://github.com/open-telemetry/opentelemetry-cpp/tree/main/examples).
 Inside each example directory is a `BUILD` file containing instructions for
 Bazel. Find the binary name of your example by inspecting the contents of this
 `BUILD` file.

README.md

@@ -1,7 +1,7 @@
 # OpenTelemetry C++
 
 [![Gitter chat](https://badges.gitter.im/open-telemetry/opentelemetry-cpp.svg)](https://gitter.im/open-telemetry/opentelemetry-cpp?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
-[![codecov.io](https://codecov.io/gh/open-telemetry/opentelemetry-cpp/branch/master/graphs/badge.svg?)](https://codecov.io/gh/open-telemetry/opentelemetry-cpp/)
+[![codecov.io](https://codecov.io/gh/open-telemetry/opentelemetry-cpp/branch/main/graphs/badge.svg?)](https://codecov.io/gh/open-telemetry/opentelemetry-cpp/)
 [![Build Status](https://action-badges.now.sh/open-telemetry/opentelemetry-cpp)](https://github.com/open-telemetry/opentelemetry-cpp/actions)
 [![Release](https://img.shields.io/github/v/release/open-telemetry/opentelemetry-cpp?include_prereleases&style=)](https://github.com/open-telemetry/opentelemetry-cpp/releases/)
 

RELEASING.md

@@ -10,7 +10,7 @@
     ```
 3. Verify that CHANGELOG.md is updated properly:
     ```
-    git diff master
+    git diff main
     ```
 4. Push the changes to upstream and create a Pull Request on GitHub.
     Be sure to include the curated changes from the [Changelog](./CHANGELOG.md) in the description.

examples/otlp/README.md

@@ -2,7 +2,7 @@
 
 This is an example of how to use the [OpenTelemetry Protocol](https://github.com/open-telemetry/opentelemetry-specification/blob/master/specification/protocol/README.md) (OTLP) exporter.
 
-The application in `main.cc` initializes an `OtlpExporter` instance and uses it to register a tracer provider from the [OpenTelemetry SDK](https://github.com/open-telemetry/opentelemetry-cpp). The application then calls a `foo_library` which has been instrumented using the [OpenTelemetry API](https://github.com/open-telemetry/opentelemetry-cpp/tree/master/api).
+The application in `main.cc` initializes an `OtlpExporter` instance and uses it to register a tracer provider from the [OpenTelemetry SDK](https://github.com/open-telemetry/opentelemetry-cpp). The application then calls a `foo_library` which has been instrumented using the [OpenTelemetry API](https://github.com/open-telemetry/opentelemetry-cpp/tree/main/api).
 
 Resulting spans are exported to the **OpenTelemetry Collector** using the OTLP exporter. The OpenTelemetry Collector can be configured to export to other backends (see list of [supported backends](https://github.com/open-telemetry/opentelemetry-collector/blob/master/exporter/README.md)).
 

examples/simple/README.md

@@ -4,7 +4,7 @@
 In this example, the application in `main.cc` initializes and registers a tracer
 provider from the [OpenTelemetry SDK](https://github.com/open-telemetry/opentelemetry-cpp).
 The application then calls a `foo_library` which has been instrumented using
-the [OpenTelemetry API](https://github.com/open-telemetry/opentelemetry-cpp/tree/master/api).
+the [OpenTelemetry API](https://github.com/open-telemetry/opentelemetry-cpp/tree/main/api).
 Resulting telemetry is directed to stdout through the StdoutSpanExporter.
 
 See [CONTRIBUTING.md](../../CONTRIBUTING.md) for instructions on building and running the example.

exporters/otlp/README.md

@@ -8,7 +8,7 @@ For a full list of backends supported by the Collector, see the [main Collector
 
 ## Configuration
 
-The OTLP exporter offers some configuration options. To configure the exporter, create an `OtlpExporterOptions` struct (defined in [exporter.h](https://github.com/open-telemetry/opentelemetry-cpp/blob/master/exporters/otlp/include/opentelemetry/exporters/otlp/otlp_exporter.h)), set the options inside, and pass the struct to the `OtlpExporter` constructor, like so:
+The OTLP exporter offers some configuration options. To configure the exporter, create an `OtlpExporterOptions` struct (defined in [exporter.h](https://github.com/open-telemetry/opentelemetry-cpp/blob/main/exporters/otlp/include/opentelemetry/exporters/otlp/otlp_exporter.h)), set the options inside, and pass the struct to the `OtlpExporter` constructor, like so:
 
 ```
 OtlpExporterOptions options;
@@ -24,4 +24,4 @@ auto exporter = std::unique_ptr<sdktrace::SpanExporter>(new otlp::OtlpExporter(o
 
 ## Example
 
-For a complete example demonstrating how to use the OTLP exporter, see [examples/otlp](https://github.com/open-telemetry/opentelemetry-cpp/blob/master/examples/otlp/).
+For a complete example demonstrating how to use the OTLP exporter, see [examples/otlp](https://github.com/open-telemetry/opentelemetry-cpp/blob/main/examples/otlp/).

ext/src/zpages/README.md

@@ -14,7 +14,7 @@ zPages are a quick and light way to view tracing and metrics information on stan
    bazel build //examples/zpages:zpages_example
    bazel-bin/examples/zpages/zpages_example
    ```
-   If you look at the [zPages example's source code](https://github.com/open-telemetry/opentelemetry-cpp/blob/master/examples/zpages/zpages_example.cc), it demonstrates adding zPages, manual application instrumentation (which sends data to zPages for viewing), and simulated use cases for zPages.
+   If you look at the [zPages example's source code](https://github.com/open-telemetry/opentelemetry-cpp/blob/main/examples/zpages/zpages_example.cc), it demonstrates adding zPages, manual application instrumentation (which sends data to zPages for viewing), and simulated use cases for zPages.
 3. View zPages at http://localhost:3000/tracez